Swing system for digging attachment



March 7, 1961 HOLOPAINEN 2,973,874

SWING SYSTEM FOR DIGGING ATTACHMENT Original Filed April 8, 1958 2 Sheets-Sheet 1 V4/N0 J. HOLOPA/NEN INVENTOR March 7, 1961 HOLOPAINEN 2,973,874

SWING SYSTEM FOR DIGGING ATTACHMENT Original Filed April 8, 1958 2 Sheets-Sheet 2 FIG. 3.

FIG. 4.

VAl/VO J. HOLOPAl/VE N IN VENTOR AORNEY SWING SYSTEM FOR DIGGING ATTACHMENT Vaino J. Holopainen, Rutland, Mass assignor to Wain- Roy Corporation, Hubbardston, Mass., a corporation of Massachusetts Continuation of application Ser. No. 651,229, Apr. 8, 1958. This appiication July 13, 1959, Ser. No. 826,882

7 Claims. (Cl. 214-132) This invention relates to a swing system for a digging attachment and more particularly to an arrangement for improved side-to-side swinging movement of ahydraulic backhoe attachment or the like for a vehicle. This application is a continuation of application Serial #651,229,

filed April 8, 1958, now abandoned.

States Patent have certain disabilities among which is the. fact that the angle through which the boom can be moved is very much limited when a cylinder of a practical size is used. In addition, the speed of swinging increases very rapidly as the extreme side positions are approached and swinging in the central positions is very slow. These and other deficiencies of the prior art have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of the invention to provide a swing system for a'hydraulic digging attachment that is capable of a wide angle of swinging.

Another object of this invention is the provision of a swing system for a backhoe or the like in which the speed of rotation at the extreme side positions is substantially the same as at the intermediate positions.

A further object of the instant invention is the provision of a hydraulic digging attachment capable of 180 swinging motion with approximately the same speed of rotation in all positions. 1

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

The character of the invention, however, may be best understood by reference to certain of its structural forms, as illustrated by the accompanying drawings in which:

Figure l a hydraulic digging attachment incorporating the principles of the present invention, Y a

Figure 2 is an enlarged perspective view of the attachment showing the swing system,

' Figure 4 is a horizontal sectional view of the invention taken on the line IVIV'-of Figure 3, but with the parts in a slightly different position.

Referring first to Figure 1, wherein are best shown the general features ofthe invention, the swing system, designatedgenerally by the reference numeral 1 0, is

shown in use in a hydraulic digging attachment '11 which is mounted on a tractor 12. The attachment '11,in--

cludes a support member 13 which is rigidly bolted to Figure 3 is a side elevational view of the swing system, and

is a perspective view of a tractor carrying of a portion top and bottom plates.

51, the other end arrangement: is connected to this system for the control of fluid flow to and from the attachment elements." The attachment 11 also includes 'a boom 15 which is: con; nected' at one: end to the lower part of the supporttmember 13 for swingingmotion about a horizontal axis; The other end'of the boom is hingedly attached to an inter.-

mediate portion of. a dipperv stick 16 for relative rotation about a horizontal axis. A bucket 17 is connected to the lower end of the dipper stick for hinged motion about a horizontal axis. A hydrauliccylinder 18' con,- nects the bucket to the upper part of the dipper stick for rotation of the bucket. A hydraulic cylinder 19 connects the upper end of. the dipper stick to the support member 13, while a hydraulic cylinder 21 connects the boom 15 at a point close to its attachment to the dipper stick and toy the support member 13 at a point adjacent its connection to the cylinder 19. The connections of the cylinders. 18, 19 and 21 to'the respectivebucket. 1:7, dipper stick 16, boom 15 and support member 13 are all for hinged movement about horizontal axes. Suitable stabilizers 22 actuated by cylinders 23 are provided.

Referring next to Figures 2, 3 and 4, it can be seen that the support member 13 consists of two parts connected together for hinged. movement about a vertical axis, i.e., a' basemember 24 and a hinge'member 25. The base member 24; which is fixed to the tractor frame, is a welded structure madeup of a vertical tube 26 to which are welded side plates 27 and 28 with suitable In plan view, the base'member has the appearance of a triangle with the tube 26 at its apex. and with the OPPOsitebase to the tractor frame.

The hinge member 25 is also a weldment and is made up of two parallel vertical plates'29 and 31, ahorizontal leg 32 at the upper'portion and another horizontal end of the-tube 26",. while a similar pintle 39 extendsupwardly from thelowerleg33, is aligned with the pintle 3S, and resides in the lower end of the tube 26. The hinge member 25 is, therefore, capable of swinging movea ment relativentothe base member 24 about-3a. generally I vertical axis defined by the .pintl'es 38 and 39. A suitable aperture- 41 provided in the upper part ofthe hinge member to provide for the pivotal, attachment of the cylinders Hand 21 thereto, while bores'42'through the lower boom 15., I i

Between the flanges 34 and 35 resides one end of a link 43 and a pin 44 joins; the link, to thefianges for hinged relative movement; a similarlink. 4S. is'pivotally portion permitthe pivotal connection ofthe attached to the flange 37' and its mate by means of'a pin 46.. The othe riend of; theIl-ink 43-isbifurcated and is pivotally attached, by means of a} pin 47, to the end of the piston rod of. a hydraulic cylinder 48; the other endof the cylinder isgpivota lly connected, in a manner not shown, to the; underside of the base member 24; .In 2 asimilar way, :the other end of. the linkASis .pivotally connectedby means of-a pin 49. to -one endof a cylinder underside of the base mernber 24.

study of Figuresg'awand 4qwill -s how thatflthe-lower leg 33. of the Iiingeniember 2'5 isprovided with a cylindrical surface '52 which is an :extensionofi thezouter/ surface Dame-tu e 26, vand, thereforekis: coaxial with thfiaxis of swinging ofthe hinge member 25.: This'siirf face isloni the; same: general level: as: the links 43: aides;

of the triangle fastened of whichg-is 'pivotally attached to the V The link 43 is provided with a protuberance 53 defining a pressure portion 54 which has a concave circular segmental shape. The portion 54 is of such a configuration and is so situated on the link that, when the link is moved about the pin 44, the portion engages snugly the cylindrical surface 52 of the hinge member. The link 45 also has a protuberance 55 which provides for a circular segmental pressure portion 56 adapted to engage the surface 52 when the link is pivoted toward the hinge member about the pin 46.

The operation of the invention will be readily understood in view of the above description. The motor of the tractor 12 is placed in idling condition and pressure oil appears in the hydraulic system. By means of the valving arrangement 14, oil under pressure is admitted or drained from the various cylinders as is desired to perform the digging operations. For instance, oil admitted to the cylinders 23 serves to depress the stabilizers 22 and force them into the ground. Oil to the cylinder 18 rotates the bucket 17, oil to the cylinder '19 rotates the dipper stick 16, and oil to the cylinder 21 rotates the boom 15, all rotations taking place, of course, in vertical planes. Admitting oil to the cylinder 51 while removing oil from the cylinder 48 causes rotation of the hinge member 25 about the axis defined by the pintles 38 and 39; this movement of the hinge member brings about a similar movement of the boom, dipper stick and allied elements. This swinging motion would be used, for instance, in removing dirt from an excavation at the rear of the tractor and loading it into a truck parked at the side.

In Figure 4 is shown the position of the elements at the end of a swing close to the extreme position at one side. The absolute extreme position, of course, would be that in which the boom extends at a right angle to the centerline of the tractor. In the position shown,

'the pressure surface 56 of the link 45 engages and presses against the cylindrical surface 52 of the hinge member. To swing in the opposite direction, the valving assembly 14 is actuated to introduce oil into the cylinder 51 and to allow it to drain from the cylinder 48. As the force is transmittted to the pin 49 from the cylinder 51, the hinge member 25 is rotated about the axis of the pintles; the force is transmitted, in effect, through a first degree lever of which the pin 49 is the end to which force is applied, the pin 46 is the end from which force is taken and the fulcrum is the contact between the portion 56 of the link and the surface 52 of the hinge member. The link 43 and the cylinder 48 are dragged in a straight line behind the pin 44, thus forcing oil out of the cylinder. Eventually, as the swinging motion continues, the pin 46 comes into line with the line of action of the cylinder 51 and the pin 49. Further motion in this direction will cause the portion 56 of the link 45 to leave the surface 52 of the hinge member, as shown in Figure 2, whereupon the link 45 becomes merely a connection between the cylinder and the hinge member, like a link in a chain which is in tension. The force due to the cylinder acts on the pin 46 and the hinge member becomes a bell crank producing a force couple about the axis of the pintles. The net effect of this mode of operation is that a swing through 90 from the center or directly rearward position involves ments produce large angular moyements of the hinge member at all parts of the swinging radius. In the prior 4 art devices, there were positions in which the lever arm was close to dead center and large cylinder movements produced only small angular swinging movements.

It is important to note that the elements must be constructed so that the circular segmental portion of a given link does not contact the cylindrical surface 52 of the hinge member until well after the corresponding portion of the other link has left the surface 52. Failure to observe this precaution will result in a jam ming action that would be injurious to the equipment.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent l. A hydraulic digging attachment for use with a vehicle, comprising a base member adapted to be secured to a vehicle, a hinge member attached to the base member for pivotal movement relative thereto about a vertical axis, the hinge member having a cylindrical surface which is co-axial with the said vertical axis, a boom connected to the hinge member for pivotal movement relative thereto about a horizontal axis, a boom-actuating hydraulic cylinder connected to the hinge member for pivotal movement relative thereto about a horizontal axis, the connection being at a point spaced vertically from the point of connection of the boom thereto, a pair of hydraulic cylinders each having one end connected to the base member, a link located adjacent each side of the hinge member, each link being pivotally connected at one end to the other end of one of said pair of hydraulic cylinders and at its other end to the hinge member at a point considerably spaced from the said vertical axis, each link having a'circular segmental intermediate pressure portion, the links being loctated on a level for engagement of the said pressure portion with the said cylindrical surface during certain portions of the swinging cycle of the hinge member about the vertical axis.

2. A'hydraulic digging attachment for use with a vehicle, comprising a base member having a vertical tube at one extremity and adapted to be secured to a vehicle, a hinge member attached to the base member by means of pintles lying within the tube for pivotal movement relative thereto about a vertical axis, the hinge member having a cylindrical surface which is co-axial with the said vertical axis and which underlies the said tube, a boom connected to the hinge member for pivotal move ment relative thereto about a horizontal axis, a boomactuating hydraulic cylinder connected to the hinge member for pivotal movement relative thereto about a horizontal axis, the connection being at a point spaced vertically from the point of connection of the boom thereto, a pair of hydraulic cylinders each having one end connected to the base member, a link located adjacent each side of the hinge member, each link being pivotally connected at one end to the other end of one of said pair of hydraulic cylinders and at its other end to the hinge member at a point considerably spaced from the said vertical axis, each link having an intermediate .pressure portion which engages a conforming portion of the hinge member at a certain part of a swinging cycle of the hinge member about the pintle axis.

3. A hydraulic digging attachment for use with a vehicle, comprising a base member having a vertical tube at an extremity and adapted to be secured to a vehicle, a hinge member attached to the base member by means of pintles lying within the tube for pivotal movement relative' thereto about a vertical axis, the hinge memqbe r having a cylindrical surface which is coaxialwith the said vertical axis and which underlies the said tube,

a boom connected to the hinge member for pivotal movement relative thereto about a horizontal axis, aboomactuating hydraulic cylinder connected to the hinge member for pivotal movement relative thereto about a horizontal axis, the connection being at a point spaced vertically from the point of connection of the boom thereto, a pair of hydraulic cylinders each having one end connected to the base member, a link located adjacent each side of the hinge member, each link being pivotally connected at one end to the other end of one of said pair of hydraulic cylinders and at its other end to the hinge member at a point considerably spaced from the said vertical axis, each link having a circular segmental intermediate pressure portion, the links being located on a level for engagement of the said pressure portion with the said cylindrical surface during certain portions of the swinging cycle of the hinge member about the vertical axis.

4. A hydraulic digging attachment, comprising a base member adapted to be secured to a vehicle, a hinge member attached to the base member by means of a pintle and tube connection for pivotal movement relative thereto about a vertical axis, a hinge member having a cylindrical surface which is co-axial with the said vertical axis and which underlies the said pintle and tube connection, a boom connected to the hinge member for pivotal movement relative thereto about a horizontal axis, a boom-actuating hydraulic cylinder connected to the hinge member for pivotal movement relative thereto about a horizontal axis, the connection being at a point spaced vertically from the point of connection of the boom thereto, a pair of hydraulic cylinders each having one end connected to the base member, a link located adjacent each side of the hinge member, each link being pivotally connected at one end to the other end of one of said pair of hydraulic cylinders and at its other end to the hinge member at a point considerably spaced from the said vertical axis, each link having a circular segmental intermediate pressure portion, the links being located on a level for engagement with the said pressure portion with the said cylindrical surface during certain portions of the swinging cycle of the hinge member about the Vertical axis.

5. A hydraulic digging attachment, comprising a base member having a vertical tube at an extremity and being adapted to be secured to a vehicle, a hinge member attached to the base member by means of pintles lying within the tube for pivotal movement relative thereto about a vertical axis, the hinge member having a cylindrical surface which is co-axial with the said vertical axis and which underlies the said tube, a boom connected to the hinge member for pivotal movement relative thereto about a horizontal axis, a boom-actuating hydraulic cylinder connected to the hinge member for pivotal movement relative thereto about a horizontal axis, a pair of hydraulic cylinders each having one end connected to the base member, a link located adjacent each side of the hinge member, each link being pivotally connected at one end to the other end of one of said pair of hydraulic cylinders and at its other end to the hinge member at a point considerably spaced from the said vertical axis, each link having a circular segmental intermediate pressure portion, the links being located on a level for engagement of the said pressure portion with the said cylindrical surface during certain portions of the swinging cycle of the hinge member about the vertical axis.

6. A hydraulic digging attachment, comprising a base member having a vertical tube at an extremity and being adapted to be secured to a vehicle, a hinge member at tached to the base member by means of pintles lying Within the tube for pivotal movement relative thereto about a vertical axis, the hinge member having a cylindrical surface which is co-axial with the said vertical axis and which underlies the said tube, a boom connected to the hinge member for pivotal movement relative thereto about a horizontal axis, a boom-actuating hyraulie cylinder connected to the hinge member for pivotal movement relative thereto about a horizontal axis, the connection being at a point spaced vertically from the point of connection of the boom thereto, a pair of hydraulic cylinders each having one end connected to the base member, a link located adjacent each side of the hinge member, each link being pivotally connected at one end to the other end of one of said pair of hydraulic cylinders and at its other end to the hinge member at a point considerably spaced from the said vertical axis, each link having an intermediate pressure portion, the links being located on a level for engagement of the said pressure portion with the said cylindrical surface during certain portions of the swinging cycle of the hinge member about the vertical axis.

7. A hydraulic digging attachment, comprising a base member adapted to be secured to a vehicle, a hinge member attached to the base member by means of a hinge connection for pivotal movement relative thereto about a generally vertical axis, a boom connected to the hinge member for pivotal movement relative thereto about a horizontal axis, a boom-actuating hydraulic cylinder connected to the hinge member for pivotal movement relative thereto about a horizontal axis, the connection being at a point spaced vertically from the point of connection of the boom thereto, a pair of hydraulic cylinders each having one end connected to the base member, a link located adjacent each side of the hinge member, each link being pivotally connected at one end to the other end of one of said pair of hydraulic cylinders and at its other end to the hinge member at a point considerably spaced from the said vertical axis, each link having an intermediate pressure portion, the links being located on a level for engagement of the said pressure portion a with the said hinge member during certain portions of the t swinging cycle of the hinge member about the vertical FOREIGN PATENTS Great Britain Apr. 7, 1927 

